GERMAN SUBMARINES IN PARTICULAR. 115 



The UC class is made up of small, coastal, mine-laying submarines. This class 

 has a surface displacement of about 500 tons and a submerged displacement of about 

 575 tons. These vessels in their latest development are about 185 feet long, 18 feet 

 beam, and 12 feet draught. They made about iij^ to 12 knots on the surface and 

 6 to "jYi knots submerged. The mines were carried in the forward part of the ves- 

 sel in non-v^atertight compartments or mine wells, 18 mines being usually carried, 

 although some of the designs carried only 12. A torpedo tube was fitted in the 

 stern and two torpedo tubes were fitted externally in the superstructure, sometimes 

 forward and sometimes abaft the conning-tower. They usually carried one 10.5 or 

 one 8.8-cm. gun. There were about 100 of these boats completed and a great many 

 more in the course of construction. 



The UB class of vessels formed the coastal submarines and were vessels of 

 about 520 tons surface displacement and 650 tons submerged. They were 183 feet 

 long, 19 feet beam and 12 feet draught. They had a surface speed of about 13^ 

 knots and a submerged speed of 7^ to 8 knots. Four torpedo tubes were installed 

 in the bow and one in the stern. They usually carried one 10.5-cm. gun; no mines 

 were carried on the UB class. 



It is of particular interest to note that the UB class and the UC class in the 

 final analysis were very similar in size and displacement. An examination of the 

 boats of these classes in Germany in December, 1918, showed very completely the 

 progressive steps made in the design and construction of these types of vessels. The 

 earlier UB boats and UC boats only displaced about 125 to 150 tons each. It was 

 very soon demonstrated that these boats were too small for the purpose intended, and 

 when standardization took place it resulted in boats as indicated above. There were 

 about 140 UB boats completed and many more under construction at the time the 

 armistice was signed. 



U-hoat — "Mittel U-boats." — The first boat of this class was completed in 1906 

 and had a surface displacement of 238 tons. The increase in the size of this type of 

 submarine continued through various progressive stages until 1914, when the dis- 

 placement had reached about 760 tons. The "mittel U-boats" subsequent to this date 

 were generally similar in design except that the displacement increased slightly so 

 that the latest type had a surface displacement of about 830 tons. The standard 

 design of "mittel U-boats" has about the following characteristics : — 



Surface displacement 830 tons. 



Submerged displacement 1,030 tons. 



Length 235 feet. 



Beam 20j^ feet. 



Draught 12}^ feet. 



Designed surface speed, about 16 knots. 

 Actual surface speed, about 15 knots. 

 Designed submerged speed, about 8^4 knots. 

 Actual submerged speed, about 8 knots or less. 



